This is a difficult work, in more ways than one, but hang in there, and check these out:

Links for more reading, more ideas, more help...

"War and Peace: Transfigured Categories and the Politics of 'Sula.'"
Just an excellent academic-minded article from the African American Review
Especially helpful in getting your mind around the deconstructive nature of the allusions Morrison uses

Cliffs Notes
Much more basic, but okay for reminders of the fundamentals, how the characters function to symbolize, or balance, or both

"'Sula' and 'Beloved': Images of Cain in the Novels of Toni Morrison"
Another article from the African American Review
Eye-opening for yet another Old Testament reference in Morrison's work -- Great if you know Beloved already

"Teacher and Student - Personal Narrative of Teaching English as a Second Language"
Article from the Humanist -- You might enjoy a short narrative about others struggling to work with this novel (just like you!) and their teacher's struggles to give them a way in (just like me!) But...it's a lot different than our story!!